Invasive Species Australia - How Much Damage Do They Cause?

Cane Toad
Cane Toad | Source

Problem of Introduced Species In Australia

Australia has a huge problem with introduced species. The world has become a much smaller place over the last few hundred years and human beings have been travelling around and migrating to other countries in unprecedented numbers. Wherever humans go they tend to take their animals with them; their pets, their farm animals and animals needed for transportation. Some animals even arrive uninvited, having hitched a lift on ships or in cargoes.

These animals either escaped or were released into the wild, and it is only in fairly recent times that the damage they have done to native species and the local environment has been acknowledged and attempts to protect the native species have been attempted.

One of the best examples here in the United Kingdom is the Grey Squirrel. They were introduced here from America around the turn of the twentieth century, and as they are bigger and much more aggressive than the native Red Squirrels, they have driven them out of much of their territory. Now only pockets of Red Squirrels remain in the remoter regions of the country.

When European settlers first started arriving in Australia in the late eighteenth century, they found a pristine environment teeming with unique animals and plants. Australia has many diverse habitats and climatic conditions, and encompasses everything from tropical, wetland species to cooler alpine species.

The settlers brought with them their domestic animals, such as cattle, horses, sheep, pigs and goats, their pets such as dogs and cats, and creatures such as rats and mice that had come along on the ships they arrived in. As times went by, even species like foxes were introduced so that the landed gentry could be reminded of their home land and carry on hunting as they had always had.

So let us have a look at some of the introduced species and see when they arrived and what impact they have had on the environment and diverse habitats of Australia.

Dingo at the Northern Territory Wildlife Park
Dingo at the Northern Territory Wildlife Park | Source
Dingoes at the Alice Springs Desert Park
Dingoes at the Alice Springs Desert Park | Source

Dingoes

A lot of people think that dingoes are native Australian animals, when in fact they only arrived four to five thousand years ago. It is believed that they came from Southeast Asia and are assumed to be descended from domestic dogs. However, in Australia they established themselves in the wild and swiftly became the apex predator. Before European settlement they were the only placental mammals in Australia apart from humans.

Dingoes are highly sociable animals that live and hunt in packs, and are highly territorial. The number of individuals in a pack varies, but is usually between 3 and 14. The pack will usually consist of an alpha male and female, and their offspring.

Dingo females produce one litter a year, and the alpha female will kill the offspring of other females in the pack if they breed. It is believed that the most genetically pure dingoes are those living on Fraser Island, as on the mainland interbreeding occurs with domestic and other feral dogs.

Dingoes have some interesting physical characteristics. They have wrists that are unique in the canine world as they can rotate, their ears are permanently erect, and they can turn their heads almost 180 degrees in each direction and howl rather than bark.

Probably the most famous dingo vocalisation in the world comes from Dinky who regularly ‘sings’ when someone plays the piano at Jim’s Place in the Northern Territory.

It is suspected that the arrival of the dingo had an impact on the ecology of Australia. Its arrival has been connected to the demise of the thylacines also known as Tasmanian Tigers, Tasmanian Devils and the Tasmanian Native-Hen from the mainland.


Camels on Cable beach at Sunset
Camels on Cable beach at Sunset | Source
Camel at Monkey Mia
Camel at Monkey Mia | Source

Feral Camels

Camels were first introduced into Australia in the nineteenth century with the first – called Harry – arriving in 1840. They were introduced as a means of transport, especially suited to the desolate, desert regions.

Indeed the famous train that runs between Adelaide and Darwin, via Alice Springs is known as the Ghan, short for Afghan Camel Train and refers to a camel route that used to run from the railhead at Oodnadatta in South Australia to Alice Springs before the rail line was extended. Camel racing also became popular and still goes on today.

Populations of camels were soon established in the wild from escaped or released animals and it is now estimated that there are now over 1,000,000 feral camels distributed over the Northern Territory, Western Australia, South Australia and the north eastern part of Queensland. Camels do not cause as much damage to the terrain as the hoofed animals that have been introduced, as their feet are adapted for desert and scrub conditions and have soft pads.

However, they do eat most plant species and can deplete the local supplies if there are too many camels in one area. They also destroy taps, pumps and cattle watering facilities in their search for water and can damage salt lake ecosystems and sand dunes, destroy fences and degrade water holes.

Feral Pig, Northern Territory Wildlife Park
Feral Pig, Northern Territory Wildlife Park | Source

Feral Pigs

Pigs were introduced into Australia by the early European settlers and inevitably some escaped or were deliberately released. It is estimated that there are now over twenty three million feral pigs living in the wild in Australia, mainly distributed in New South Wales, Queensland and the top of the Northern Territory.

Feral pigs are highly destructive to the environment as they root for their food and rip out plants by their roots. This destroys the native ecosystems as it is very difficult for the native plant life to re-establish itself, which leads to soil erosion and weeds taking over. Feral pigs are also opportunistic predators and scavengers and can decimate local populations of reptiles, birds, bird’s eggs, insects and small mammals.

As pigs are susceptible to the heat, they are drawn to water holes, rivers and wetlands, and again, their wallowing and digging behaviours are highly damaging to sensitive ecosystems and native species. They also have the potential to carry and spread a lot of diseases such as Foot and Mouth, leptospirosis, encephalitis and brucellosis.

Feral pigs also cause a great deal of damage to Australia’s agricultural industry, as they damage fences, pasture, water supplies, and prey heavily on lambs and goats.

Feral Bull, Ord River, The Kimberley
Feral Bull, Ord River, The Kimberley | Source
Feral Bull, Ord River, The Kimberley
Feral Bull, Ord River, The Kimberley | Source

Feral Cattle and Water Buffaloes

Cattle were also introduced into Australia by the early European settlers and vast tracts of the country are now used as cattle stations containing huge numbers of cattle. As we have seen before, some of these cattle escape or were released and have formed wild populations. As cattle are a hoofed animal they cause a great deal of damage to the fragile soil and ecosystems of Australia, causing soil erosion

They are also big animals so do damage to trees and shrubs as they move around the bush and can destroy riverbanks and the edges of water holes by churning them up with their hooves. As herbivores, they also consume a large quantity of native plant life, thus depriving the native species and depleting the environment.

Water buffaloes were introduced into the northern parts of Australia in the nineteenth century to supply meat to remote areas. The buffaloes were abandoned and they then bred in the wild and spread rapidly.

Their numbers soared and they destroyed precious wetland environments and spread diseases. Mass culling, in the form of The Brucellosis and Tuberculosis Eradication Campaign, was introduced in the 1970s and early 1980s and the numbers of feral water buffaloes in the wild has severely declined.

Smaller Australian Feral Animals

Many smaller introduced species have also been incredibly destructive. Foxes and cats devastate populations of native wild life, and mice and rats get into grain stores, destroy crops and compete with native species for food and space.

Rabbits have spread across most of Australia, despite the 1700 kilometre Rabbit-Proof fence being constructed in Western Australia. Rabbits destroy plants and shrubs; compete with the native species and cause soil erosion.

Probably the newest arrival is the Cane Toad, which was introduced in the 1930’s to eat the beetles that were ravaging the sugar cane crops in Queensland. They failed to contain the beetles and are now spreading over ever growing swathes of Australia. They are harmful to native species as they are highly venomous and when another animal attempts to eat them they die of poisoning, they also prey on native species and compete with native amphibians for living and breeding space in ponds and water courses.

Wetlands Near Darwin, Northern Territory

Wetlands near Darwin, Northern Territory
Wetlands near Darwin, Northern Territory | Source

Control of Feral Animals in Australia

Feral animals in Australia are controlled by a number of methods including traditional methods such as fencing, shooting, poison baits and trapping and using biological controls such as introducing species-specific diseases and using contraception to slow down breeding.

Much emphasis is now placed on control programmes being humane and causing as little suffering to the animals as possible, and also taking into consideration how they may be now important in the ecosystem or economy in some local areas. After all, it is not their fault that they are there!

Not all attempts at control work, for example an attempt to control rabbits with a disease called mxyomatosis was attempted in the 1950s, which proved to be initially successful but resistance to the disease has built up in the rabbit population. Great attempts are now made to preserve existing pristine ecosystems, such as those on islands; as these are often the last colonies of some native species.

There are also some big projects, such as Project Eden on the Peron Peninsula in the Shark Bay area, where major attempts are being made to root out all feral animal and plant species and return the area to an entirely native ecosystem.

An electric fence has been built at the neck of the peninsula to stop any more feral animals gaining entry and human traffic enters over a cattle grid that emits the sound of a dog barking when weight is placed on it to deter feral animals from crossing the grid. Existing native species are now thriving and other native species are slowly being re-introduced. You can even join in and experience feral animal control as there are tour companies that take tourists out trapping feral pigs or even shooting feral bulls!

Copyright 2009 CMHypno on HubPages

Cane toad image Froggydarb Wikimedia Creative Commons Attribution Share Alike 3.0 Unported

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Comments 29 comments

CMHypno profile image

CMHypno 19 months ago from Other Side of the Sun Author

Thanks for reading and commenting on the hub Blackspaniel1. Invasive species are a huge problem the world over, costing billions to local economies and destroying ecosystems.


Blackspaniel1 profile image

Blackspaniel1 19 months ago

There is always a temptation to introduce a species for a purpose, and problems often follow. In this area we have nutria eating the area to destruction, and water lilies clogging waterways.


CMHypno profile image

CMHypno 4 years ago from Other Side of the Sun Author

Glad that you enjoyed reading the hub Suhail. Unfortunately we humans have taken invasive species and disease with us wherever we go, and it is only recently that we really realised what problems in native ecosystems that we had caused.


Suhail and my dog profile image

Suhail and my dog 4 years ago from Mississauga, ON

Great hub - exactly to my taste.

I am reading recently published book 'Rat Island' by William Stolzenberg. It talks about how island ecologies were destroyed by explorers like Polynesians and Europeans due their hunting, farming, and introducing invasive species. The book also documents conservationists' success in getting island rid of invasive species, especially rats, in New Zealand (with respect to Kakapos) and North America. Your hub has done a great job in providing information as it applies to Australia.


CMHypno profile image

CMHypno 5 years ago from Other Side of the Sun Author

Hi PaperNotes, thanks for reading the hub and leaving a great comment. I think that there is always going to be a conflict in trying to preserve native eco-systems and humanely treating invasive species. Of course, the ideal situation is that alien species are just not introduced in the first place, but since that has already happened in so many parts of the world, just what is the best method of stopping invasive species from totally overwhelming local wildlife populations?


PaperNotes profile image

PaperNotes 5 years ago

Maybe these animals really should not be in Australia as they originated from other lands. Yet it should not mean that we ought to rightfully eliminate them in whatever way possible. I mean, they are also creatures deserving to live a life on this earth. It is probably this attitude of man that is also slowly killing Mother Earth, the lack of consideration.


Mizzy 5 years ago

umm its gr8!


Spoony Galoony profile image

Spoony Galoony 6 years ago from Melbourne, Australia

Good hub! I'm new to HP and my first hub has been about feral rabbits. Even after all the research I have done into the topic to prepare for my hub, I still learned a lot from this one and has given me ideas for future hubs (while staying original!) :)


CMHypno profile image

CMHypno 6 years ago from Other Side of the Sun Author

Glad you enjoyed reading about invasive species in Australia, Michael


Michael Shane profile image

Michael Shane 6 years ago from Gadsden, Alabama

Interesting hub! Enjoyed the read..


CMHypno profile image

CMHypno 6 years ago from Other Side of the Sun Author

All living things in nature should be treated with respect. But, generally by human intervention, animal, plant and insect species have established themselves in areas where they do not occur naturally. Australia has many unique eco-systems and habitats, and some invasive species are causing a great deal of harm and disruption to the native Australian wildlife. The hard part is always how to protect native habitats, while still dealing with invasive species humanely.


marijanareynders profile image

marijanareynders 6 years ago from Toodyay, Western Australia

I care deeply for nature and ALL things living, great or small. Any positive information on how to protect and safeguard our environment, contributes enormously to ensuring the co-existence of all life. A question: If all the continents were joined at a stage, doesn't it imply that we are all, man and beast, citizens of the world, with all of us having equal rights to exist, and that species of life are not country-bound? If I look around me, it seems that if we remove man out of the equation, all natural life might continue for millions of years. We, humans, are the greatest destroyers of our natural habitat.


CMHypno profile image

CMHypno 7 years ago from Other Side of the Sun Author

Thanks for stopping by stricktlydating and leaving a great comment. We have some big spiders around here, but luckily they are not venomous!


stricktlydating profile image

stricktlydating 7 years ago from Australia

Nice Hub. We have many more creepy crawlies here - some native - which I wish weren't here too. Try living with deadly spiders and snakes in the backyard! No Dingo's Camels or wild pigs living near me though thankfully!


CMHypno profile image

CMHypno 7 years ago from Other Side of the Sun Author

Thanks for the wonderful comment, Peggy W. It is indeed a worldwide occurrence, and there is probably no way of rolling it all back, but just as much effort as possible is needed in protecting the local wildlife and plants.


Peggy W profile image

Peggy W 7 years ago from Houston, Texas

I believe that almost every part of the world has had plant and animal species introduced to it either by accident or on purpose and often the endemic plants and animals are the ones to suffer the consequences...along, of course, with humans. Very informative hub!


CMHypno profile image

CMHypno 7 years ago from Other Side of the Sun Author

Hi salt, thanks for the great comment. Thylacines or Tasmanian Tigers were native to continental Australia, but became extinct thousands of years before European settlement. The introduction of the dingo has been put forward as a possible cause of their demise, as they would have been competing against the dingoes for prey and territory.

We have mystery big cats in the UK too - Exmoor is a popular spot for sighting and livestock are quite regularly found killed in a way that it looks like a large cat is responsible.


salt profile image

salt 7 years ago from australia

Thankyou that was really good. I am unsure about the dingos and the eradication of the tasmanian tiger, as I thought they were native to tasmania and not mainland australia.

There are mystery panthers or feral cats too. I saw one in Western Australia, which was larger than a Kelpie dog, but the farm cat won a fight with it in a tree and it fell, landed on a wheelbarrow and ran away.

We used to ride motor bikes along the rabbit proof fence and emu proof fence - for hours.


CMHypno profile image

CMHypno 7 years ago from Other Side of the Sun Author

Thanks for the great comments about Tenerife, Bard of Ely. Yeah, where did cockroches originally come from? It's an exceptionally complex subject, and animal welfare must be an important part of the equation. To a certain extent all evolution has been based on migration and climate changes, but i suppose a balance needs to be found where the native species are not being subsumed by the incomers. Bet it's not raining in Tenerife!


Bard of Ely profile image

Bard of Ely 7 years ago from Lisbon, Portugal

A lot of what lives and grows on Tenerife where I now live was brought here eg Prickly Pear cacti, Century Plant Agaves, Monarch Butterflies and Mediterranean Treefrogs - all common over the island but none are from here originally. And then of course there are the Cockroaches!

We also have Egyptian Fruit Bats and efforts to eradicate them. I know a lady who filmed some and made a video she put online and asked me what they were. When I told her she said she was taking the video down because she didn't want to think that revealing their location could get them killed.

The real problem is who has the right to play God and decide what can and cannot live in a place it wasn't from in the first place? And who can say for sure where anything originated from? And if it is OK for humans to colonise any part of the globe then why not other animals and plants? So many questions!


Amanda Severn profile image

Amanda Severn 7 years ago from UK

I knew that the camels and pigs were introduced, but had no idea that dingoes were. It's surprising what you can learn on hubpages!


CMHypno profile image

CMHypno 7 years ago from Other Side of the Sun Author

Hi Bard of Ely, Shalini Kagal, marcofratelli, thanks for the great comments. It's true that it's not just animals but plants and insects being introduced that cause problems to the native species - Harlequin Ladybirds in the UK being a great example.

A sad little story in the paper yesterday is that there used to be a colony of wallabies in the Peak District in the UK that had grown from some escapees from a private collection. It was believed that the colony was more or less wiped out in the cold winter of 1963, with only a few survivors. The picture in the article was of a lone wallaby in the Peak District, and experts think that this is the last one left. Poor, lonely little wallaby!


marcofratelli profile image

marcofratelli 7 years ago from Australia

Cool hub! As an Aussie fella, even I didn't know that all of these animals were introduced. :)


Shalini Kagal profile image

Shalini Kagal 7 years ago from India

Interesting and informative thank you. Animals, birds, plants - we really do mess up, don't we? The sad thing is, we're the ones who have to suffer the onsequences!


Bard of Ely profile image

Bard of Ely 7 years ago from Lisbon, Portugal

It's yet another example of how people mess up the world and what the answer is I really don't know because it is obvious that people will go from one part to another and always have done. And it is not just animals because there are countless plant invaders in all parts of the world where non-endemic species have arrived and colonised new territory often at the extent of native species.

Excellent hub!


CMHypno profile image

CMHypno 7 years ago from Other Side of the Sun Author

Thanks for the great comment Jerilee Wei. It is, indeed, a huge problem worldwide and how it's being dealt with in different countries is fascinating - the re-introduction of the wolves into the Yellowstone Park is one of the most interesting I have come across


Jerilee Wei profile image

Jerilee Wei 7 years ago from United States

Very interesting, especially about the cattle and the camels. Non-native species are a world-wide problem.


CMHypno profile image

CMHypno 7 years ago from Other Side of the Sun Author

Thanks for the great comment emohealer. Introduced species of animals, insects and plants are a problem in a lot of countries.


emohealer profile image

emohealer 7 years ago from South Carolina

I had no idea. Thanks for a very informative and educational article on a subject that impacts all of us and for some (me) who are not as aware as we might think we are.

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